1. Field of the Invention
The present disclosure relates to image processing apparatuses, recording media, and method.
2. Description of the Related Art
With respect to image data with low resolution, whose color thickness, brightness, etc., are expressed in gradation, there is a technique of outputting an image from an image processing apparatus with high resolution, after executing a process of increasing pixel density along a main-scanning direction or a sub-scanning direction in accordance with the resolution of the image processing apparatus and executing a gradation process.
Such a technique is embodied by, for example, an image processing apparatus provided with a multi laser diode (LD). For example, the image processing apparatus receives image data with low resolution constituted by pixels whose color thickness, brightness, etc., are expressed in gradation of 16 levels (i.e. gray level). Then the image processing apparatus writes the pixels (hereinafter referred to as multivalued pixels) included in the image data on a memory, and then reads out the pixels from the memory multiple times, so as to duplicate the multivalued pixels. Then, the image processing apparatus executes an edge correction, a trimming process, etc., on the image data constituted by the duplicated multiple multivalued pixels.
Then, the image processing apparatus segments the multivalued pixels, for example, into more than a hundred smaller-sized regions. Then, the image processing apparatus determines, with respect to each of the segmented regions, whether to light with an LD (i.e. whether to be a lighted region or a non-lighted region) based on the gray level of the duplicated multivalued pixels, with reference to a look up table (LUT) corresponding to the multiple duplicated multivalued pixels. The image processing apparatus performs binary processing for outputting an image on a print sheet, outputting a predetermined color on the lighted regions and not outputting color on the non-lighted regions.
Furthermore, there is a technique of executing γ conversion, using a LUT regarding gray level data of an input image and using phase data of an output image, so as to control emission of an LD (for example, see Japanese Unexamined Patent Application Publication No. 2007-215214).